Injection molding machines for high speed production of plastic items use multiple cavity molds. A typical machine producing plastic bottle caps for example may produce eighty to one hundred caps per injection cycle. At the end of an injection cycle, all the caps will be ejected simultaneously from the mold, and will fall downwardly between the space between tie bars or rods on which the movable mold section is slidably mounted. Unless an expensive and complex guide of some kind is provided, some of the caps occasionally may strike the tie bars which are always copiously covered with lubricant.
There is a growing inclination on the part of some customers to reject a whole shipment if just a few parts are "contaminated" with oil or grease from the tie rods.
To eliminate any possible such contact between molded parts and greasy tie bars, one company supplies a special guide package comprising a fabric guide skirt, chutes, and mold side curtains, to guide the parts directly from the mold, past the greasy tie bars to a container or conveyor in the bottom of the machine. This "package" is expensive, costing in the neighborhood of $200.00 and requires a special one for each different size injection molding machine.